1. Field of the Invention
The present invention relates to a polycrystalline CaF2 member, to a member for a plasma treatment device, to a plasma treatment device, and to a method for producing a focusing ring.
2. Description of Related Art
As a plasma resistant member for a semiconductor manufacturing device, a focusing ring comprising a plurality of members has been known from Japanese Laid-Open Patent Publication 2009 290087 and Japanese Laid-Open Patent Publication 2011 3730.